Casing



FIG. 1 is a perspective view of the casing showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a rear side view thereof.

The broken lines in the drawings illustrate the portions of the casing that form no part of the claim. 

CLAIM The ornamental design for a casing, as shown and described. 